title: The effect of abaxial retraction on pelvic geometry after pelvic symphysiotomy.
abstract: OBJECTIVE
  To describe the effect abaxial retraction after pelvic symphysiotomy has on the geometry of the sacroiliac joints (SIs) in dogs.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Canine cadavers (n = 9).
  
  
  METHODS
  Canine cadavers free of sacroiliac disease had pelvic symphysiotomy and retraction to 25%, 50%, 75%, and 100% of transverse sacral width, followed by axial reduction of the symphysis. Before symphysiotomy, after each abaxial retraction value, and after reduction of the symphysis each SI joint had a computed tomographic scan to evaluate the effect on the SI joints.
  
  
  RESULTS
  There was no luxation at 25% abaxial retraction, unilateral SI luxation in three cadavers after 50% abaxial retraction and in all cadavers after 75% abaxial retraction. Axial reduction of the symphysis resolved all luxations.
  
  
  CONCLUSIONS
  Pelvic symphysiotomy and abaxial retraction between 50% and 75% of transverse sacral width leads to unilateral SI luxation, which is resolved by axial reduction. While not likely requiring ancillary stabilization, SI joint luxation may be a cause for additional postoperative pain, reluctance to ambulate, and prolonged hospitalization/recovery.
authors.affiliation: Department of Clinical Studies, Veterinary Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Schlicksup
authors.forename: David E
authors.initials: DE
authors.lastname: Holt
authors.forename: Wilfried
authors.initials: W
authors.lastname: Mai
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Holmes
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Agnello
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D004285:Dogs; D005260:Female; D008297:Male; D012446:Sacroiliac Joint / Q000033:anatomy & histology*; D013567:Symphysiotomy / Q000379:methods / Q000662:veterinary*